Background: Intensive care unit-acquired pneumonia (ICU-AP) is a severe complication in patients admitted to the ICU. Lymphocytopenia is a marker of poor prognosis in patients with community-acquired pneumonia, but its impact on ICU-AP prognosis is unknown. We aimed to evaluate whether lymphocytopenia is an independent risk factor for mortality in non-immunocompromised patients with ICU-AP. Methods: Prospective observational cohort study of patients from six ICUs of an 800-bed tertiary teaching hospital (2005 to 2016). Results: Of the 473 patients included, 277 (59%) had ventilator-associated pneumonia (VAP). Receiver operating characteristic (ROC) analysis of the lymphocyte counts at diagnosis showed that 595 cells/mm3 was the best cut-off for discriminating two groups of patients at risk: lymphocytopenic group (lymphocyte count <595 cells/mm3, 141 patients (30%)) and non-lymphocytopenic group (lymphocyte count ≥595 cells/mm3, 332 patients (70%)). Patients with lymphocytopenia presented more comorbidities and a higher sequential organ failure assessment (SOFA) score at the moment of pneumonia diagnosis. Also, 28-day mortality and 90-day mortality were higher in patients with lymphocytopenia (28-day: 38 (27%) versus 59 (18%), 90-day: 74 (53%) versus 111 (34%)). In the multivariable model, <595 cells/mm3 resulted to be an independent predictor for 90-day mortality (Hazard Ratio 1.41; 95% Confidence Interval 1.02 to 1.94). Conclusion: Lymphocytopenia is an independent predictor of 90-day mortality in non-immunocompromised patients with ICU-AP.
Rapid identification of the causative agent of hospital-acquired pneumonia (HAP) will allow an earlier administration of a more appropriate antibiotic and could improve the outcome of these patients. The aim of this study was to develop a rapid protocol to identify the main microorganisms involved in HAP by loop-mediated isothermal amplification (LAMP) directly from respiratory samples. First of all, a rapid procedure (<30 min) to extract the DNA from bronchoalveolar lavage (BAL), endotracheal aspirate (EA) or bronchoaspirate (BAS) was set up. A specific LAMP for Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Acinetobacter baumannii was performed with the extracted solution at 65 °C for 30–40 min. Overall, 58 positive BAL and 83 EA/BAS samples were tested. The limits of detection varied according to the microorganism detected. Validation of the LAMP assay with BAL samples showed that the assay was 100% specific and 86.3% sensitive (positive predictive value of 100% and a negative predictive value of 50%) compared with culture. Meanwhile for BAS/EA samples, the assay rendered the following statistical parameters: 100% specificity, 94.6% sensitivity, 100% positive predictive value and 69.2% negative predictive value. The turnaround time including sample preparation and LAMP was circa 1 h. LAMP method may be used to detect the most frequent bacteria causing HAP. It is a simple, cheap, sensitive, specific and rapid assay.
Background: Low physical activity and high sedentary behaviour in patients with bronchiectasis are associated with hospitalisation over one year. However, the factors associated with longitudinal changes in physical activity and sedentary behaviour have not been explored. We aimed to identify clinical and sociodemographic characteristics related to a change in physical activity and sedentary behaviour in patients with bronchiectasis after one year. Methods: This was a prospective observational study during which physical activity measurements were recorded using a SenseWear Armband for one week at baseline and at one year. At each assessment point, patients were classified as active or inactive (measured as steps per day) and as sedentary or not sedentary (measured as sedentary time). Results: 53 patients with bronchiectasis were analysed, and after one year, 18 (34%) had worse activity and sedentary levels. Specifically, 10 patients became inactive and sedentary. Multivariable analysis showed that the number of exacerbations during the follow-up period was the only outcome independently associated with change to higher inactivity and sedentary behaviour (odds ratio (OR), 2.19; 95% CI, 1.12 to 4.28). Conclusions: The number of exacerbations in patients with bronchiectasis was associated with changes in physical activity and sedentary behaviour. Exacerbation prevention may appear as a key factor in relation to physical activity and sedentary behaviour in patients with bronchiectasis.
Ventilator-associated pneumonia (VAP) is a well-known complication of patients on invasive mechanical ventilation. The main cause of acute respiratory distress syndrome (ARDS) is pneumonia. ARDS can occur in patients with community-acquired or nosocomial pneumonia. Data regarding ARDS incidence, related pathogens, and specific outcomes in patients with VAP is limited. This is a cohort study in which patients with VAP were evaluated in an 800-bed tertiary teaching hospital between 2004 and 2016. Clinical outcomes, microbiological and epidemiological data were assessed among those who developed ARDS and those who did not. Forty-one (13.6%) out of 301 VAP patients developed ARDS. Patients who developed ARDS were younger and presented with higher prevalence of chronic liver disease. Pseudomonas aeruginosa was the most frequently isolated pathogen, but without any difference between groups. Appropriate empirical antibiotic treatment was prescribed to ARDS patients as frequently as to those without ARDS. Ninety-day mortality did not significantly vary among patients with or without ARDS. Additionally, patients with ARDS did not have significantly higher intensive care unit (ICU) and 28-day mortality, ICU, and hospital length of stay, ventilation-free days, and duration of mechanical ventilation. In summary, ARDS deriving from VAP occurs in 13.6% of patients. Although significant differences in clinical outcomes were not observed between both groups, further studies with a higher number of patients are needed due to the possibility of the study being underpowered.
2 May 2023 in Frontiers in Cellular and Infection Microbiology
Introduction: Biofilm production is an important yet currently overlooked aspect of diagnostic microbiology that has implications for antimicrobial stewardship. In this study, we aimed to validate and identify additional applications of the BioFilm Ring Test® (BRT) for Pseudomonas aeruginosa (PA) isolates from patients with bronchiectasis (BE).Materials and methods: Sputa were collected from BE patients who had at least one PA positive culture in the previous year. We processed the sputa to isolate both mucoid and non-mucoid PA, and determined their susceptibility pattern, mucA gene status, and presence of ciprofloxacin mutations in QRDR genes. The Biofilm production index (BPI) was obtained at 5 and 24 hours. Biofilms were imaged using Gram staining.Results: We collected 69 PA isolates, including 33 mucoid and 36 non-mucoid. A BPI value below 14.75 at 5 hours predicted the mucoid PA phenotype with 64% sensitivity and 72% specificity.Conclusion: Overall, our findings suggest that the fitness-cost associated with the mucoid phenotype or ciprofloxacin resistance is shown through a time-dependent BPI profile. The BRT has the potential to reveal biofilm features with clinical implications.
9 December 2023 in International Journal of Antimicrobial Agents
Background: The effect of systemic treatment of ventilator-associated pneumonia (VAP) with telavancin, a semisynthetic lipoglycopeptide with good penetration in vitro biofilms, has not been tested in vivo during mechanical ventilation. This study examined the efficacy of telavancin compared with linezolid against endotracheal tube (ETT) biofilms in a porcine model of methicillin- resistant Staphylococcus aureus (MRSA) VAP. Methods: VAP was induced in 18 pigs by instilling 107 colony-forming units (CFU/mL) of a MRSA strain susceptible to telavancin and linezolid into each pulmonary lobe. Randomization into three groups was done at pneumonia diagnosis: control (IV glucose 0.5% solution q24); linezolid (10 mg/kg q12) and telavancin groups (22.5 mg/kg q24). After 72h of MV, data regarding bronchoalveolar lavage (BAL), tracheal aspirate (TA), ETT MRSA biofilm load and thickness measured by scanning electron microscopy were obtained. Results: All 18 pigs completed the study. MRSA was isolated in 100% of ETTs from the control and linezolid groups, and in 67% from the telavancin group. Telavancin treatment presented lower MRSA load compared to the control and linezolid treatments (telavancin median [interquartile range (IQR)] =1.94 [0.00-5.45], linezolid 3.99 [3.22-4.68] and control 4.93 [4.41-5.15], p=0.236). Telavancin treatment also resulted in the lowest biofilm thickness according to the SEM (4.04 [2.09-6.00], p<0.001). We found a positive correlation between ETT and BAL load (rho=0.511, p=0.045). Conclusions: In our VAP model, systemic telavancin treatment reduced ETT MRSA occurrence, load, and biofilm thickness. Our findings may have a bearing on ICU patients' clinical outcomes.